Nitrates??

[cecilsgarden1958]

What does the Nitrate-N ppm level mean on a soil test? Mine is way up from last year. Is this a residue from last season or is this actually Nitrogen?

CECIL

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SOIL TEST SPRING 2008
Performed by Penn State University-$9

Soil PH
7.0
Optimum

Phosphate
1040 lb/A
Above Optimum

Exchangeable Cations (meq/100g)
Acidity
0.0
Potash
0.9
Magnesium
2.3
Calicium
22.8

CEC (Cation Exchange Capacity)
18.2
% Saturation of the CEC

Potash
4.8
Optimum

Magnesium
12.8
Above Optimum

Calcium
82.4
Above Optimum


Optional Tests-additional fee
Organic Matter-18.2%
Nitrate-N ppm 104.4
Soluablle Salts-mmhos/cm 0.09


Recommendations:
Limestone-None
Magnesium-None
Gypsum-None
Phosphate-None
Potash-None
Nitrogen-Apply 0.5 lbs of Urea per 100 sq foot

[amideutch]

Cecil, people dream about having results as you had with your soil tests. Here is a couple links that might help. Ami

https://www.certifiedcropadviser.org...am_pdf/113.pdf

http://cropsoil.psu.edu/Extension/Facts/agfact17.pdf

[cecilsgarden1958]

Originally Posted by amideutch

Cecil, people dream about having results as you had with your soil tests. Here is a couple links that might help. Ami

https://www.certifiedcropadviser.org...am_pdf/113.pdf

http://cropsoil.psu.edu/Extension/Facts/agfact17.pdf

Ami: Got anything that isn't a pdf file? My crappy webtv doesn't do pdf.

CECIL

[amideutch]

Cecil, I'll cut and paste the meat of the article. Ami

The nitrate soil test is not new. One of the first scientists to analyze soils for water soluble nitrate-N as a
means of estimating the plant available N pool was King in Wisconsin in 1901 (Dahnke and Johnson
1990). Almost 60 years later, Leggett found that nitrate-N was a useful indicator of plant available N in
Washington soils (Dahnke and Johnson 1990) and Soper found similar results for Manitoba soils (Figure
1). Soper and Huang (1963) also examined the effectiveness of the soil organic matter test, an incubation
test and a test for easily hydrolyzed N as methods for predicting the N supply for barley.

In spite of its overall success, the nitrate test fails periodically, especially in cases where the soil may
contain large amounts of organic N that may be mineralized during the growing season. Therefore, when
the nitrate test is evaluated across many different types of sites and years, the accuracy appears to less
than that observed in some of the early research trials with the test.

Crops can utilize ammonium or nitrate forms of N; however, annual crops, in particular, take up nitrate as
their main source of N. Ammonium N still plays a very important role in crop nutrition, although that
role is often indirect, as a result of bacterial nitrification of the ammonium to nitrate prior to crop uptake
of the N. The soil’s ammonium-N supply is regularly replenished from several sources, including soil
organic matter, manure, crop residues and fertilizers. At the same time, some of the ammonium N can be
immobilized into organic N by soil microorganisms. The processes of immobilization of plant available
N and mineralization of organic N from soil organic matter, manure and crop residues are the “wild
cards” that can make prediction of the soil’s N supply very difficult, especially when using conventional
soil tests, where only the nitrate form is measured.

[amideutch]

Cecil, heres one more. Ami

Nitrogen Soil Test
A new approach to N soil testing whereby samples are
taken during the growing season has been under study by
researchers across the country, including a major effort in
Pennsylvania. This test is called the Pre-sidedress Soil
Nitrate Test (PSNT). The basis for this new N soil testing
approach is taking soil samples just before sidedressing—
after the spring wet period but before the period of major N
demand by corn—and determining the nitrate-N available
in the soil at that time. The results are then used to make
sidedress N recommendations.
Research has shown that when the soil nitrate-N level is
above 21 ppm, there is little chance of an economic
response to adding additional N to the field. At soil nitrate-
N levels below 21 ppm, sidedress N will be required to
achieve optimum economic yield. The table below can
be used to estimate an appropriate N recommendation in
this situation.

[cecilsgarden1958]

Just got another notice separately by mail that says my ammonium nitrogen is 6.45.

CECIL

P. S. Does anybody know if any of this nitrate and nitrogen info affects me for this season?? If not I wil post it in the soil forum.